On Tue, Aug 25, 2015 at 09:28:13PM -0400, Dan Williams wrote: > Given that: > > 1/ device ->remove() can not be failed > > 2/ a pmem device may be unbound at any time > > 3/ we do not know what other parts of the kernel are actively using a > 'struct page' from devm_memremap_pages() > > ...provide a facility for active usages of device memory to block pmem > device unbind. With a percpu_ref it should be feasible to take a > reference on a per-I/O or other high frequency basis. Without a caller of get_page_map this is just adding dead code. I'd suggest to group it in a series with that caller. Also if the page_map gets exposed in a header the name is a bit too generic. memremap_map maybe? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>